Interaction Between Host, Microenvironment and Immunity on Gastrointestinal Neoplasms

Blood collection (50 ml) will be performed for all patients at baseline, at 1 month post-operative for resected patients (+ at the end of neoadjuvant treatment / before surgery if patient receives neoadjuvant treatment), and at 2-3 months after the beginning of the treatments in patients with metastases (+ at each progression). Following analysis should be performed with * serum for protein assays and characterization analysis of cytokines, new tumor markers and micro-RNA ...; * plasma for protein assays and characterization analysis of micro-RNA, VEC (the content of proteins, RNA, micro-RNA and DNA) and metabolomics; * PBMC for flow cytometry analysis, isolation macrophages; * whole blood for circulating tumor DNA (mutations by NGS, ddPCR,…; methylation) and circulating tumor cells.

An intraoperative liver biopsy will be performed at free edge of liver with a triangular sample for local resected patients. This biopsy will be done with scissors, then patients will receive intraoperative hemostasis with mono- or bipolar coagulation. This procedure will be under laparoscopy or laparotomy without extending standard processing time. This biopsy seeks to allow the evaluate liver modifications testifying the preparing for premetastatic niche, which would allow to identify the patients with risk for hepatic relapsing; the same analysis on the tumors will be performed.

Stool collection will be performed for all patients at baseline, at 1 month post-operative for resected patients (+ at the end of neoadjuvant treatment / before surgery if patient receives neoadjuvant treatment), and at 2-3 months after the beginning of the treatments in patients with metastases (+ at each progression). Analysis will be performed for microbiota and metabolism analysis.